Propeller not cycling

[Gary Wallace]

Need help please. Initial start ..not brand new engine. Lycoming O360. Hartzell overhauled constant speed propeller. New jhistrol propeller governor. I installed propeller, and yes I removed the crank plug and installed O ring in rear of propeller. I installed governor with supplied gasket with screens. Everything torqued to specs. Warmed engine and oil, tried cycling propeller many times with no response. Oil was up to 140 degrees.. also, I did have rpm to 2100 a few times.. any suggestions anyone? This is my first experience with CS prop and governor.

[jaredyates]

When you say you tried cycling the prop, how long did you pull the knob back for? Keeping in mind that there probably wasn't much of any oil in the prop, it may take several seconds to get enough oil in to make it work. I'd say if it isn't working in 20 seconds with the knob full back, then you have a problem.

[Mark Goldberg]

Sometimes it takes longer than you think to get oil circulating in a governor. Just today I had a call back from a customer who could not get his governor to work. Tried and tried. Full power runups (couple of times) still nothing. But then it started working. I know the Hartzell governor sometimes takes 1900+ rpm to cycle. Mark

[Gary Wallace]

I had good oil pressure...I believe 75 psi...I pulled governor lever at least 30 times...again I thought maybe cool oil could be an issue. I warmed it up pretty good. I did think it May take a while to get oil to hub since this engine had a fixed pitch prop on originally. I did have prop control pulled a few times for maybe 15 seconds. I did clear some oily gunk out of crank shift from front when I pulled plug out. It wasn't horrible but cleaned it up real good. Not sure what to try next....a bit frustrating since all is new...except engine. Any chance of a blocked oil passage from governor to hub? I don't know where it exactly or but....

[Nev]

Gary, I had a similar experience. Don't panic (yet). The issue with mine was that I have a "narrow deck" engine (older) and they apparently put out a lower oil pressure to the governor. The modern governors apparently are set up for a wide deck engine, with a higher oil pressure. Hence mine wouldn't cycle fully at 1800rpm.

Hartzell said there is a setting inside the governor that can be set for a narrow deck engine. That can be done by a prop shop and mine will be done at a later date.

Prior to discovering the reason we had also removed the prop, removed the governor etc and done a lot of head-scratching and cursing.

[schu]

https://vansairforce.net/community/showthread.php?t=203788

[Gary Wallace]

Thanks for all the great information...will be digging into this shortly...will see how I make out!

[Mark Spickard]

Where did the prop come from? Are the prop and the governor both of the “pressure to increase pitch” type? Single engine aircraft typically use a system where an increase in pressure will increase the prop pitch. If there is some sort of failure in the system, the pressure will likely go to zero, the prop will go to low pitch, the engine will be able to produce high rpm and the aircraft can still fly, albeit slowly…….stuck in first gear. Twin engine aircraft use systems where an increase in pressure will decrease the prop pitch. A failure will lead to low pressure, high pitch…..feathered, min drag from the dead engine and continued flight on the good engine. Aerobatic aircraft also have pressure to decrease pitch as they often have momentary loss of oil supply to the governor while already at high rpm. A momentary loss of pressure leads to a momentary increase in pitch and momentary reduction of rpm, not a momentary and destructive increase in rpm. If you have a PIP governor and a PDP prop, when at low rpm the governor will command low pressure to the prop which means max prop pitch. Even at max power the engine may not get to sufficient rpm to get the governor “on speed”, and this may be the case no matter what the governor setting is via the prop lever……move the lever around and nothing happens. If it does get on speed, the governor will increase pressure, the prop pitch will decrease and the engine will quickly over rev……dont what this to happen.

[Gary Wallace]

Governor and propeller are both increase pressure increase pitch for sure. For those in the know,, rear mounted governor O360, if I disconnect the tube at the governor pad are that runs to the front crankcase, and blow 40 pounds of air in there to the front crankcase,, the prop should turn course pitch at the hub yes? I believe I am correct here. Thanks all.im thinking big problem with leakage,rear cap missing? Or a plug missing in the internalbcrankcase at front causing oil bypass. From what I have found doing my homework ...not good

[robcaldwell]

Are you using steam gauges, or EFIS? I am using Dynon and learned that my EFIS was not set up from the factory for my engine, therefore indicating a higher RPM than the engine was actually turning. When I set the EFIS to match my engine, I got the actual RPM's. Even still, my lightweight Trailblazer prop does not cycle until 2,000 RPM's.

[Gary Wallace]

I am using efis...and I am still not sure of my rpm but...I do believe it is correct...by ear and experience...of course I will confirm later...I was running..by my efis...2200 for minute or more....no wings on...chocked and tied up.....no luck. If I did my pressure check properly, I've got a lot of work to do. I'm learning lots of what I should have done....I believe . 40 psi air into crank at front case. Air all bleeding through and out into engine,,,out oil filler etc. Looks like I'll be pulling engine and splitting..unreal....

[Gary Wallace]

So......rear crank plug DOES have a hole in it. Good 7/16 inch...what options do I have...I'm afraid!

[Gary Wallace]

It's actually an 11/32 hole...anyway that can be plugged without a tear down?.

[Chris Werner]

Gary Wallace does anything in this service letter help? I believe on some cranks the rear plug can be serviced without teardown. https://www.lycoming.com/sites/defau...ce%20Versa.pdf

[Chris Werner]

Post 15 in this link has a picture of the tool made to replace the rear plug.

https://vansairforce.net/community/showthread.php?t=167258&page=2

[Rollie]

This forum is a great resource for Bearhawk specific stuff but I wouldn't get too close to tearing into an engine based on what you find here without first speaking with an A&P who is experienced with the engine - prop - governor setup you are running and maybe having one come and check out what you have. There is some great experience here, but for the most part we are amateurs. (ya know - the A in EAB) Maybe you do need to tear your engine open, but maybe this is something that a guy with 20 years experience working on these engines can diagnose and remedy in a few minutes. Could save you lots of time and money.